M The Use of Lasers and Intense Pulsed Light for Treating Melasma

Transcription

M The Use of Lasers and Intense Pulsed Light for Treating Melasma
Managing Melasma
The Use of Lasers and
Intense Pulsed Light for
Treating Melasma
Series Editor:
Doris Hexsel, MD
Henry H.L. Chan, MBBS, MD, FRCP
M
elasma is a common acquired pigmentary condition. It often affects the face in a symmetrical pattern and, because of its visible nature,
can have a significant psychological impact. There are
3 clinical subtypes of melasma: epidermal, which presents as bilateral light brown macules and patches affecting both cheeks and the face; dermal, or Hori’s macules,
which presents as speckled or confluent brownish-blue
or slate gray pigmentation over the face; and mixedtype, which is a combination of both subtypes.
Conventional treatment includes using a combination
of topical bleaching agents. Hydroquinone, tretinoin, vitamins C and E, a-hydroxy acid, kojic acid, and azelaic acid
are effective but often result in an incomplete response.
Lasers and intense pulsed light have recently been used as
a novel treatment for this distressing condition.
The results of previous studies have discouraged the
use of lasers in treating melasma. More than a decade
ago, Grekin et al1 concluded that the pulsed dye
510-nm laser could not remove melasma and could
increase pigmentation. Melasma was later shown to
resist treatment with the Q-switched ruby laser (QSRL),
regardless of fluence (7.5–15 J/cm2).2 There was no
permanent improvement; in some cases, hyperpigmentation developed. These findings are consistent with
the author’s experience. In epidermal and mixed-type
melasma, hyperpigmentation may occur following treatment with a pigment laser. The cause for such unwanted
effects is unknown but likely related to the pathogenesis
of melasma. It has been suggested that in epidermal and
mixed-type melasma, characterized by epidermal hyperpigmentation, the pathogenesis involves increased melanocytes and increased activity of melanogenic enzymes
overlying solar radiation–induced dermal changes.3 This
recent observation may explain why hyperpigmentation may develop after treatment with a pigment laser.
Increased melanogenic enzyme activity suggests that
melanocytes are hyperactive. Sublethal laser damage
to these melanocytes by a pigment laser may increase
melanin production from these melanocytes and result
in hyperpigmentation.
The photomechanical effect of the QS laser may also
contribute to increased risk of hyperpigmentation.4 The
QS laser generates high-energy radiation with very short
pulse duration and produces intense energy leading to
rapid temperature rise (1000°C) within the target subcellular chromophore. When the laser pulse duration is
shorter than the thermal relaxation time of the target, a
temperature gradient is created between the target and
its surrounding tissue. When the temperature gradient collapses, localized shock waves are generated that
cause fragmentation of the target. This photomechanical reaction leads to the melanosomal disruption that
is seen after QS laser irradiation. Studies that examined
the use of the QS laser and the long-pulsed 532-nm
Nd:YAG laser in the removal of lentigines in patients
with dark skin indicated that the long-pulsed 532-nm
laser is associated with lower risk of postinflammatory
hyperpigmentation (PIH).5 The long-pulsed laser differs from the QS laser in that it has a photothermal,
but not photomechanical, effect. Intense pulsed light
(IPL), which emits a broad band of visible light from
a noncoherent filtered flashlamp, also produces only
photothermal effects. Recent studies of IPL used in
removing lentigines in Asian patients have confirmed
its effectiveness.6,7 No cases of PIH were observed in
several independent studies. Studies of IPL and of the
long-pulsed 532-nm Nd:YAG laser have confirmed that
the photomechanical effects of the QS laser are unacceptable and may lead to increased pigmentation.8,9
In addition to unwanted photomechanical effects,
the wavelengths used may be associated with adverse
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Dr. Chan is Honorary Clinical Associate Professor, Department
of Medicine, University of Hong Kong, China, and Department of
Medicine and Therapeutic and Department of Pediatrics, Chinese
University of Hong Kong, China.
Dr. Chan is a stockholder for Reliant Pharmaceuticals, LLC.
VOL. 20 NO. 2 • FEBRUARY 2007 • Cosmetic Dermatology®
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Copyright Cosmetic Dermatology 2010. No part of this publication may be reproduced, stored, or transmitted without the prior written permission of the Publisher.
Managing Melasma
effects. For a 510-nm pulsed dye laser or a 532-nm
Nd:YAG laser, the wavelengths are absorbed by hemoglobin as well as melanin. Purpuric macules may occur
and correlate with the histological changes of erythrocyte coagulation within the superficial vessels. Damage
to the superficial vessels leads to inflammation and
consequent PIH.
Sunblock should, whenever possible, contain zinc
oxide and titanium dioxide and be applied 1 hour
before any outdoor activity and every 3 hours thereafter. Many combinations of tretinoin, hydroquinone,
topical steroid, a-hydroxy acid, kojic acid, or azelaic
acid have been used as topical bleaching agents.10,11 In
the author’s practice, tretinoin 0.05% cream mixed with
hydroquinone 4% and fluocinolone acetonide 0.01%
is the preferred combination. Despite the application
of a topical steroid, this combination may still cause
irritation. In such cases, mometasone furoate may offer
some relief. Once a patient tolerates topical treatment,
other bleaching preparations, including glycolic acid,
vitamins C and E, and kojic acid, may be added. In
addition, the author performs a mild glycolic acid peel
(concentration, 35%; duration, 2–5 minutes) monthly
for 2 to 3 months before commencing laser or IPL surgery. Patients are advised to continue sun protection
postoperatively. To avoid irritation, topical bleaching
agents should be resumed 5 days after laser or IPL surgery rather than immediately following the surgery.
A spot test should be performed on all patients with
epidermal or mixed-type melasma. To treat epidermal
or mixed-type melasma, the long-pulsed laser (532-nm
potassium titanyl phosphate or Nd:YAG) or IPL is preferred. The suggested parameters for IPL in Asian patients
are listed in the Table. For the long-pulsed 532-nm
Nd:YAG laser, the clinical end point is an ashen gray
appearance of the treated skin (suggested parameter,
6.5-J/cm2 fluence; 2-ms pulse width; 2-mm spot size).
To avoid vascular injury and the associated increased risk
of hyperpigmentation, the vasculature should be compressed and hemoglobin removed from the vessel. Both
actions may be achieved by pushing the IPL handpiece
to the skin or, for the laser, by attaching a convex contact
window to the handpiece and then pushing the window
to the skin (R.R. Anderson, personal communication,
December 2001). The QS laser is best avoided or, if necessary, used with the lowest fluence and largest spot size
(QS 1064-nm Nd:YAG, 1.4-J/cm2 fluence; 6-mm spot
size). In all patients, topical mometasone furoate should
be applied immediately following laser or IPL surgery.
Despite these precautions, increased pigmentation occurs
in 10% to 15% of patients; such risks should be emphasized before treatment. Mixed-type melasma appears to
be associated with greater risk of hyperpigmentation than
epidermal melasma and may be associated with functionally abnormal melanocytes that extend to the appendageal rather than just the epidermis.
Resurfacing lasers have also been used with some
success in treating melasma. The aim of the ablative
laser is to remove only the abnormal melanocytes that
are thought to be found along the basal layer of the
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Suggested Intense Pulsed Light Parameters for Asian Patients*
Wavelength (nm)
Energy (J/cm2)
Mean
Range
Palomar (Estelux® Pulsed Light System; LuxG™ Pulsed Light Handpiece)
500–670; 870–1400
28
17–30
Ellipse
400
8
8
Aurora
580
25; RF, 20
20–28
Quantum
560
640
23
30
19–29
24–35
VascuLight™
550–590
36
33–55
*RF indicates radiofrequency.
82 Cosmetic Dermatology® • FEBRUARY 2007 • VOL. 20 NO. 2
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Managing Melasma
A
B
Acquired bilateral nevus of Ota-like macules before laser treatment (A) and after 9 treatments with the Q-switched alexandrite
laser (8 J/cm2)(B).
epidermis. The melanocytes along the appendageal are
normal. Manaloto and Alster12 treated 10 patients with
refractory melasma with the Er:YAG laser. Significant
improvement was seen 3 to 6 weeks later, but biweekly
glycolic acid peels were required. Angsuwarangsee and
Polnikorn13 compared the combined carbon dioxide
laser and QS alexandrite laser (QSAL) with the QSAL
alone in treating refractory melasma. The combined
approach yielded better results but was associated with
more adverse effects, including PIH that occurred in
2 out of 6 patients. These findings suggest that functionally abnormal melanocytes are unlikely to be confined to
the epidermal basal layer.
Chemical peeling performed immediately after the
use of a pigment laser has also been used with some
success in a series of patients with a range of pigmentary conditions, including melasma and freckles. 14
As these patients had mixed etiology, it is difficult to
assess whether epidermal or mixed-type melasma alone
responds well to such combined treatment.
Fractional skin resurfacing is a new development
that uses a 1540-nm laser to create microscopic spots
of thermal injury that are surrounded by healthy skin
tissue.15 As the area of thermal injury is very small, the
lateral migration of keratinocytes occurs rapidly, leading
to complete re-epithelialization of the epidermis within
24 hours. Recent studies have indicated that it may be
used effectively for treating epidermal melasma, with
significant improvement in 60% of patients and mild
improvement in 30%.16,17 Although improvement may
certainly occur after such treatment, the recurrence rate
is not yet known, and longer-term follow-up is necessary to assess the efficacy of this treatment.
dermal melasma (Figure). The reason is that ABNOMs,
like epidermal or mixed-type melasma, present as
acquired hyperpigmentation that usually affects the
bilateral malar regions. However, as the lesions are a
form of dermal melanosis, they appear clinically as bluish rather than brown. Epidermal melasma frequently
coexists with ABNOMs. Other areas of the face may also
be affected, including the temples, the root of the nose,
the alae nasi, the eyelids, and the forehead.18,19
The use of the QS laser has generated much interest.
Previous work with the QSRL (7- to 10-J/cm2 fluence,
1-Hz repetition rate, 2- to 4-mm spot size) indicated
that complete clearance could be obtained in more than
90% of patients treated.20 There was no recurrence after
6 months to 4.3 years (mean, 2.5 years) of follow-up.
PIH was common, affecting 7% of patients. The QS
1064-nm Nd:YAG laser is also effective, but PIH affects
50% to 73% of patients treated with this laser.21,22 A
more recent retrospective analysis of 32 female Chinese
patients treated with the QSAL (755 nm, 8-J/cm2 fluence, 3-mm spot size) concluded that 80% of patients
had greater than 50% clearance and more than 28%
had complete clearance (Figure, B).23 Patients with
posttreatment PIH were given topical hydroquinone
and tretinoin cream. Patients underwent a mean of
7 treatment sessions (range, 2–11), with a mean treatment interval of 33 days. Results were assessed by
2 independent observers. Hyperpigmentation occurred
in 12.5% of the patients but resolved in all cases following treatment with topical bleaching medication.
In a pilot study, carbon dioxide laser followed immediately by the QSAL was effective in treating dermal
melasma in 4 patients.24 More recently, epidermal ablation with the scanned carbon dioxide laser followed
immediately by the QSRL has also been shown to be
effective and achieved a greater degree of improvement
than the QSRL alone. Transient hypopigmentation was
the main adverse effect.25
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The Use of Lasers for Treating Acquired
Bilateral Nevus of Ota-Like Macules
Acquired bilateral nevus of Ota-like macules (ABNOMs),
or Hori macules, have frequently been classified as
VOL. 20 NO. 2 • FEBRUARY 2007 • Cosmetic Dermatology®
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Copyright Cosmetic Dermatology 2010. No part of this publication may be reproduced, stored, or transmitted without the prior written permission of the Publisher.
Managing Melasma
Current research suggests that ABNOMs are more
resistant to treatment than nevus of Ota; there is a higher
rate of postoperative pigment disturbance. Thus, all
patients should be prescribed topical bleaching agents
both preoperatively and postoperatively. The author’s
practice is to treat such patients more frequently, with
laser procedures repeated every 4 weeks. The intention
is to treat the area before epidermal repigmentation
occurs. In doing so, more laser energy can reach the
dermal target chromophore through a hypopigmented
epidermis without the competitive absorption of epidermal melanin. For resistant cases (failure to improve
after 4 treatment sessions), QSAL treatment is followed
immediately by QS Nd:YAG treatment. The fluence
should be lower (4–5 J/cm2 for both lasers), and the
repetition rate should be reduced (to ≤3.3 Hz) to lower
the risk of adverse effects. Nevertheless, transitory pigmentary disturbance still occurs, and patients should
be warned of this before starting treatment. It has been
claimed that IPL may be used for treating dermal pigmentation, including ABNOMs. However, the author’s
opinion is that this approach can be associated with a
high risk of scarring and should not be endorsed.
6. Kawada A, Shiraishi H, Asai M, et al. Clinical improvement of
solar lentigines and ephelides with an intense pulsed light source.
Dermatol Surg. 2002;28:504-508.
7. Negishi K, Wakamatsu S, Kushikata N, et al. Full-face photorejuvenation of photodamaged skin by intense pulsed light with
integrated contact cooling: initial experiences in Asian patients.
Lasers Surg Med. 2002;30:298-305.
8. Rashid T, Hussain I, Haider M, et al. Laser therapy of freckles and
lentigines with quasi-continuous, frequency-doubled, Nd:YAG
(532 nm) laser in Fitzpatrick skin type IV: a 24-month follow-up.
J Cosmet Laser Ther. 2002;4:81-85.
9. Chan HH. Treatment of photoaging in Asian skin. In: Rigel DS,
Weiss RA, Lim HW, et al, eds. Photoaging. New York, NY: Marcel
Dekker Inc; 2003:343-364.
10. Chan HH, Alam M, Kono T, et al. Clinical application of lasers in
Asians. Dermatol Surg. 2002;28:556-563.
11. Goldman MP. The use of hydroquinone with facial laser resurfacing. J Cut Laser Ther. 2000;2:73-77.
12. Manaloto RM, Alster T. Erbium:YAG laser resurfacing for refractory melasma. Dermatol Surg. 1999;25:121-123.
13. Angsuwarangsee S, Polnikorn N. Combined ultrapulse CO2 laser
and Q-switched alexandrite laser compared with Q-switched
alexandrite laser alone for refractory melasma: split-face design.
Dermatol Surg. 2003;29:59-64.
14. Lee GY, Kim HJ, Whang KK. The effect of combination treatment
of the recalcitrant pigmentary disorders with pigmented laser and
chemical peeling. Dermatol Surg. 2002;28:1120-1123.
15. Manstein D, Herron GS, Sink RK, et al. Fractional photothermolysis: a new concept for cutaneous remodeling using microscopic
patterns of thermal injury. Lasers Surg Med. 2004;34:426-438.
16. Tannous ZS, Astner S. Utilizing fractional resurfacing in the treatment of therapy-resistant melasma. J Cosmet Laser Ther. 2005;7:
39-43.
17. Rokhsar CK, Fitzpatrick RE. The treatment of melasma with
fractional photothermolysis: a pilot study. Dermatol Surg. 2005;
31:1645-1650.
18. Hori Y, Kawashima M, Oohara K, et al. Acquired, bilateral nevus
of Ota-like macules. J Am Acad Dermatol. 1984;10:961-964.
19. Mizoguchi M, Murakami F, Ito M, et al. Clinical, pathological, and
etiologic aspects of acquired dermal melanocytosis. Pigment Cell
Res. 1997;10:176-183.
20. Kunachak S, Leelaudomlipi P, Sirikulchayanonta V. Q-switched
ruby laser therapy of acquired bilateral nevus of Ota-like macules.
Dermatol Surg. 1999;25:938-941.
21. Kunachak S, Leelaudomlipi P. Q-switched Nd:YAG laser treatment for acquired bilateral nevus of ota-like maculae: a long-term
follow-up. Lasers Surg Med. 2000;26:376-379.
22. Polnikorn N, Tanrattanakorn S, Goldberg DJ. Treatment of
Hori’s nevus with the Q-switched Nd:YAG laser. Dermatol Surg.
2000;26:477-480.
23. Lam AY, Wong DS, Lam LK, et al. A retrospective study on the
efficacy and complications of Q-switched alexandrite laser in
the treatment of acquired bilateral nevus of Ota-like macules.
Dermatol Surg. 2001;27:937-941.
24. Nouri K, Bowes L, Chartier T, et al. Combination treatment of
melasma with pulsed CO2 laser followed by Q-switched alexandrite laser: a pilot study. Dermatol Surg. 1999;25:494-497.
25. Manuskiatti W, Sivayathorn A, Leelaudomlipi P, et al. Treatment
of acquired bilateral nevus of Ota-like macules (Hori’s nevus)
using a combination of scanned carbon dioxide laser followed
by Q-switched ruby laser. J Am Acad Dermatol. 2003;48:
584-591.
n
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Conclusion
Lasers and IPL may be used for treating melasma. For
epidermal and mixed-type melasma, hyperactivity of the
functional melanocytes must be treated first before performing a spot test to assess the clinical efficacy of lasers
and IPL. Fractional resurfacing is a new technology that
may be used for treating epidermal and mixed-type
melasma. A longer-term study is necessary to assess the
recurrence rate after improvement with fractional resurfacing. The QS laser should be used to treat ABNOMs,
but IPL should be avoided since it is associated with a
greater risk of scarring in dermal pigmentation.
References
1. Grekin RC, Shelton RM, Geisse JK, et al. 510-Nm pigmented
lesion dye laser: its characteristics and clinical uses. J Dermatol
Surg Oncol. 1993;19:380-387.
2. Taylor CR, Anderson RR. Ineffective treatment of refractory
melasma and postinflammatory hyperpigmentation by Q-switched
ruby laser. J Dermatol Surg Oncol. 1994;20:592-597.
3. Kang WH, Yoon KH, Lee ES, et al. Melasma: histopathological characteristics in 56 Korean patients. Br J Dermatol. 2002;146:228-237.
4. Chan H. The use of lasers and intense pulsed light sources for the
treatment of acquired pigmentary lesions in Asians. J Cosmet Laser
Ther. 2003;5:198-200.
5. Chan HH, Fung WK, Ying SY, et al. An in vivo trial comparing the
use of different types of 532 nm Nd:YAG lasers in the treatment
of facial lentigines in Oriental patients. Dermatol Surg. 2000;26:
743-749.
84 Cosmetic Dermatology® • FEBRUARY 2007 • VOL. 20 NO. 2
Copyright Cosmetic Dermatology 2010. No part of this publication may be reproduced, stored, or transmitted without the prior written permission of the Publisher.